Method of casting phosphorized copper



Dec. 10, 1935. R. HEWGILL METHOD OF CASTING PHOSPHORIZED COPPER FiledFeb. 1, 1934 INVENTOR ATTORNEYS.

Patented 7 Dec. 10, 1935 I PATE T OFFICE METHOD OF CASTING PHOSPHOBIZEDCOPPER Russell Hewgill, Sudbury, Ontario, Canada, assignor to TheAmerican Metal Company, Limiegi New York, N. Y., a corporation of New 7application February 1, 1934, Serial No. 709,303

This invention relates to the casting of phosphori'red copper, and maybe used for the casting of other deoxidized copper alloys. Phosphorizedcopper is a deoxidized copper containing a 5 residual amount ofphosphorus as a deoxidizing component and a alyzes approximately .02 percent. phosphorus. I

The casting of phpsphorized copper involves considerable difliculty. Itmust be cast under very different conditions from those required in thecasting of electrolytic copper or tough pitch fire refined copper. Forthese the molds must be heated preferably inthe neighborhood of 100 C.and the mold surfaces or casting cavity dressed 15 with awash of boneash. For phosphorized copper, on the contrary, the mold must be keptcold-a.

. and the mold dressing is an 011 mixture.

.Ih'the' production of phosphorized copper the addition of phosphorus inthe form of a rich phosphoriz'ed copper alloy to the molten copper bathimparts certain characteristics ,to the bath' which make vit difficultto obtain a satisfactory casting unless special precautions are taken..

Phosphor copper when coming into contact with air appears to form acertain amount of a compound very rich in phosphorus,.assaying as high88-33% P, which compound when it comes in contact with the cold moldsurface almost immediately sets and causes a hole or depression in 30.the finished casting, making it unsuitable for ordinary commercial uses.In order to avoid this result, a stream women-excluding gas,

v such as a gas containing carbon monoxide. produced in a charcoal orother fuel gas producer,

as is directed into the mold during the casting procedure, however, doesnot in itself produce a satisfactory casting although somewhat betterthan when air is not excluded, as it ap- 40 pears that the mold dressingi s not completely.

decomposed by the heat of the molten copper, and there remains on themold walls a solid decomposition product of the oil which also pre-.ventsthe production of a satisfactory surface on Q '45 the finishedcasting.

I have discovered that by adding water to the mold the difficultiesheretofore encountered are avoided, resulting in the production ofcopper cakes, billets or other castings, having a satis- 50 factorysurface condition, with no perceptible increase in the internal porosityof the casting.

Water may be variously added to provide a awater' film coating on thewalls of the casting cavity by first introducing a pool of water into($6 the mold which may be drained therefrom prior to pouring the moltenmetal, or by spraying water into the-mold during the pouring, or byintroducing a stream of water together with the pour ing, or byintroducing atomized water, or a spray or fog or other moist conditioncarriedv into the 5 mold with the producer gas. The use of water isadvantageous either with or without the use of such gas in casting.

The preferable mode of practicing the invention is as follows: Thecasting may be accoml0 plished in any known or suitable mold, preferably in an upright mold'of copper cooled'by circuiation of water througha surrounding water jacket. After the mold dressing is applied, water issprayed into the mold over the sides of the 15 cavity and at the bottomthereof; then, during the pouring, .as soon as the metal within the moldhas formed a substantial pool (to a depth of two or three inches, forexample) water is added to the mold in a small stream or spray in 20sufficient quantity so that a fairly large poolzof water is kept on thesurface of the molten metal, preferably both in front of and behind thestream of metal entering .the mold. When sufllcient water has been thusadded the water stream may 25 be shut down, or may be diminished so thatthe additional water introduced is only suilicient to just compensatefor'the loss in evaporation.

The. use of water in this manner appears to serve two purposes; thewater sprayed on the sides of the mold cavity is transformed into steamwhen the hot metal makes contact'with it, and the bubbles of steam thusformed appear to prevent the high phosphor compound or slag from cominginto contact with the sides of the cold mold and congealing thereon. Theforce ofthe steam thus ,generated appears to be suillcient to throw thiscompound, together with any carbon formed from the decomposition of theoil dressing, towards the center of the mold, where it is 40 caught inthe larger pool of water and kept floating or suspended therein untilthe mold is filled with the copper, and in this manner it is preventedfrom coming into contact with the sides of the mold'and congealingthereon in the manner which heretofore 'gave trouble in creating acavity in the surface of the casting.

Satisfactory results have been obtained with both vertical cake moldsand vertical round billet molds. It is preferable but not essential toin-- 'troduce producer gas into the mold prior to and during 'thepouring.- This use of gas is advantageous, but is not necessary in the.casting of billets; but in the casting of cakes it has greateradvantage, and in some cases appears to be a cavity as indicated inFigs. 1 A metal isto be cast without 'spout and ladle may be hoodedoverin the well mold cavity is closed necessary procedure to theattainment of successful castings.

It is impossible to state with exactness the quantity 01' water to beadded during the east ing. In casting billets the interior of the moldafter dressing should be sprayed withwater until its surface is totallycovered with fine drops. For such casting this alone has proved asuflicient addition of water,- althoughit is desirable also to introducea fine stream into the mold during the pouring period. The water may beintroduced in the form of steam, although this has not proved assatisfactory as a spray of water.

"In the casting of copper cakes, experience has indicated that it isimportant to spray the mold with water before any metal is added andthere-' after to continue introducing water in a stream or spray insuflicient quantity to maintain always a small pool on the moltencopper, which should be bothin front of and behind the metal stream. Thepool of water which is maintained on the surface of the molten metalneed only be of sufficient depth to float and prevent the slag or drosscontaining the phosphorus from coming in contact with the molten metalor the sides 01' the cold metal.

While it is practicable to introduce the water in the form of steam orwater vapor or atomized water intothe stream of producer gas which isintroduced into the mold, this method does not have .any advantage over.the introduction of water directly through a small pipe, and .thelatter is believed to afiord greater facility for the control of theintroduction of water.

No special apparatus is required, but as an illustration of suitablemeans reference may be made to the accompanying drawing, wherein- Figs.1 and 2 show respectively in vertical section and in partial horizontalsection a vertical mold for castingrectangular copper cakes; and

Figs. 3 and 4 are similar views showing a vertical billet or ingot moldfor casting cylindrical billets "or analogous shapes.

Fig. 5 is a sectional elevation of pipes for introducing water and gastogether into the furnace.

this being provided by forming a closely related B communicating atbottom with a passage extending around within the mold wall andreceiving cooling water from an inlet D; and united at the top in apassage E extending around within the upper wall of the mold, whence thewater issues through an outletF'. The bottom of the by a-door G, whichmay be hinged as shown in Fig. 3 and .held up by a bail H or othersupport wedged beneath it, by removing which the door may be droppedopen and the casting dumped out. Such molds are'known and regularly usedfor makinslcopper castings.

The phosphorized. copper is taken from the furnace or other container bya spout H, whence it pours into a ladle J of usual construction, whichmay rest on the top of the from which the metal pours and '3. When theaccess 01' air, the

known manner to form a chamber into which suitable oxygen-excludinggas'is introduced.

All these features form the customary casting means and require noalteration in the practice of the present invention. j For casting undergas protection, it is common In the drawgig, A designates the mold,which is water-jackete series ofvertical ducts or bores mold as shown,and' over intothe mold' to cover over the top of the mold with a'p'lateK through an opening in which gas is introduced through a pipe L, asshown in Figs. 1 and 2.

For the introduction of water in the form of jets or spray or steam, anysuitable. pipe may be employed, an exampleof which is shown at M. Thismay be an iron pipe coupled at its top to a hose N. This pipe may beintroduced through the free potu'ing space to the right of plate K, asshown in Figs. 1 and through the plate K, as shown in Fig. 3, in case noseparate gas pipe L is used. The pipe M is freely movable up and downand may be grasped by tongs or otherwise manipulated bythe oper- 2; orit may be introduced 6 ator, who will initially lower it and turn onsu1- 5 without it. Any suitable valve P is provided within convenientreach of the operator by which he can control the flow of water.

If the water is to be introduced with the gas it is desirable to sprayor atomize the water into the stream of gas, which may as shown in Fig.5 where the water is introduced under pressure through a pipe Q undercontrol of a valve, into an atomizing, commingling nozzle R, to whichgas is conducted through a pipe S, and the flow of commingled gas andspray or mixture is conducted thence through the pipe L to the mold.

As one example, it may be stated that experience has shown-that suitableresults are secured be accomplished 2.4 litres (3 H. oz. to 2.6 qts.) isused with a mold wherein the pouring occupies a very short period; sayaround 15 .seconds, and more with larger molds where the pouring takeslonger, as for ex: ample, with a 600 lb. over 2 minutes; but success maybe attained when lessor even more water is us v I It will be obvious tothose skilled in the copper casting art that the mode of introducing thewateror mixture into the mold may be greatly varied without departingfrom the present invention;

While the described process has proven highly eflicacious and valuablewith, phosphorized cop:

per, it appears to be also available for improving the casting of othercopper alloys having similar casting, which may take 40 to be due partlyto the me- -a black slaggy material .and is so far eliminated 0 by thesolvent action of the water as to avoidits occlusion in the casting..The invention is accordingly applicable to other copper alloys,

wherein a water soluble oxide or compound is produced during the castingoperation. It may 05 V perhaps also be'available in the case 01 thosealloys wherein the compound formed during castiifg is not water soluble,as in the case of copper containing silicon; but its applicability tothe casting of such other alloys has not yet been den termined.

-What I claim is:

1. The process of casting deoxidized containing a small prising coatingthe copper amount of deoxidizer. comwallsof the casting cavity.

. comprising introducing water into the mold so as to provide a waterfilm coating on the walls of the casting cavity preliminary to thepouring of the molten metal and providing a pool of water in the moldabove'the molten metal of merely sufiicient depth to float the dross, byintroducing water into the mold together with the molten metal after apool of metal has formed in the mold.

4. The process of casting deoxidized copper according to claim 2 whereinthe water is introduced into the mold in subdivided form.

5. The process of casting deoxidized copper according to claim 2 whereinthe water is introduced into the mold in the form of steam.

6. The process of casting deoxidized copper according to claim 2 whereinthe water is introduced into the mold together with an oxygen-excludinggas. a

7. The process of casting deoxidized copper according to claim 2 whereinthe water is introduced into the mold together with gas containingcarbon monoxide.

8. The process of casting deoxidized copper alloys containing a smallamount of deoxidizer, comprising dressing the walls of the castingcavity with an oil mixture, providing a water film coating upon saiddressed walls preliminary to the pouring oi the molten metal, andintroducing water into the mold during the pouring oi the molten metal.

9. The process of casting deoxidized copper alloys consisting indressing the walls of the casting cavity with an oil mixture, providinga water 5 film coating upon said dressed walls preliminary to thepouring of the molten metal, and introducing water into the mold duringthe pouring of the molten metal to provide a pool of water in the moldabove the pool of molten metal;

10. The process of casting phosphorized copper comprising coating thewalls of the casting cavity with a film of water preliminary to pouringthe molten metal, and introducing water during the pouring of the moltenmetal to provide a pool of water in the mold above the pool of moltenmetal of merely sufilcient depth to float the dross, and adding saidwater in amounts to compensate for evaporation of water from the mold tomaintain the pool of water above the molten metal in the mold.

11. The process of casting deoxidized copper, comprising pouring moltenmetal into a mold, and after ,a pool of metal has been formed therein,introducing water into the mold during the pouring of the molten metalin merely sufiicient quantity to provide and maintain a pool of waterabove the surface of the molten metal to fioat the dross and tocompensate for evaporation of water from the pool, said pool of waterhaving no practical cooling effect upon the molten metal.

12. The process of casting deoxidized copper, comprising pouring moltenmetal into a mold, and after a pool of metal has been formed therein,introducing water in subdivided forminto the mold during the pouring ofthe molten metal in merely sufilcient quantity to provide and maintain apool of water above the surface or the molten metal.

RUSSELL HEWGILL.

CERTIFICATE oF' CORRECTION.

Patent no. 2,023,957. I Q December 10, 19:55.

RUSSELL HEWGILII.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,first column, lihe 26, for "metal" read mold; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealedthis 28th day of January, A. D. 1936.

Leslie-Frazer (Seal) Acting Commissioner of PatentB.

